<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="utf-8">
		<title>w0923_2</title>	
	</head>

	<body>
		<script>
			//var 변수명 
			var value=10;
			value+=20; //value=20
			document.write("value값:"+value +"<br/>");
			document.write("typeof value:" + typeof value +"<br/>");
			document.write("typeof value:" + typeof true +"<br/>");
			document.write("typeof value:" + typeof function(){} +"<br/>");
			document.write("typeof value:" + typeof {} +"<br/>");
			document.write("typeof value:" + typeof a +"<br/>");
			//변수를 선언(값을 할당x)만하고 확인하면 undefined
			
			var value="hello";
			document.write("value값:"+value); //????
		</script>
	</body>
</html>
